docs: def combine(files: List[str], output_file: str, key: str = None, file_attrs: Dict[str, str] = None, batch_size: int = 1000, convert_attrs: bool = False) -> None:
  	"""
  	Combine two or more loom files and save as a new loom file
  	Args:
  		files (list of str):    the list of input files (full paths)
  		output_file (str):      full path of the output loom file
  		key (string):           Row attribute to use to verify row ordering
  		file_attrs (dict):      file attributes (title, description, url, etc.)
  		batch_size (int):       limits the batch or cols/rows read in memory (default: 1000)
  		convert_attrs (bool):   convert file attributes that differ between files into column attributes
  	Returns:
  		Nothing, but creates a new loom file combining the input files.
  		Note that the loom files must have exactly the same
  		number of rows, and must have exactly the same column attributes.
  		Named layers not present in the first file are discarded.
  		.. warning::
  			If you don't give a ``key`` argument, the files will be combined without changing
  			the ordering of rows or columns. Row attributes will be taken from the first file.
  			Hence, if rows are not in the same order in all files, the result may be meaningless.
  		To guard against this issue, you are strongly advised to provide a ``key`` argument,
  		which is used to sort files while merging. The ``key`` should be the name of a row
  		atrribute that contains a unique value for each row. For example, to order rows by
  		the attribute ``Accession``:
  		.. highlight:: python
  		.. code-block:: python
  			import loompy
  			loompy.combine(files, key="Accession")
  	"""
  	if file_attrs is None:
  		file_attrs = {}
  
  	if len(files) == 0:
  		raise ValueError("The input file list was empty")
  
  	copyfile(files[0], output_file)
  
  	ds = connect(output_file)
  	for a in file_attrs:
  		ds.attrs[a] = file_attrs[a]
  
  	if len(files) >= 2:
  		for f in files[1:]:
  			ds.add_loom(f, key, batch_size=batch_size, convert_attrs=convert_attrs)
  	ds.close()